The intent of our research is to ascertain the relationship between vitamin A and lung cancer. This study will be carried out in a unique population (Louisiana) known to have very high incidence of lung cancer and suspected to have suboptimal intakes of vitamin A. From available data, we will investigate the association of death rates due to lung cancer with average vitamin A serum levels and vitamin A intakes in parishes (counties) with high and low incidence of lung cancer. These data should provide a crude index which may give insights into the role of vitamin A in the epidemiology of lung cancer. We will also perform case control studies in which dietary intakes and vitamin A concentration in hepatic tissue for patients who died of lung cancer will be compared with appropriate controls. Studies will also be performed in living patients suffering from lung cancer. Serum level concentrations and dietary intakes of vitamin A will be evaluated and compared with matched (age, sex, race, hospital) controls. In the course of these studies we will have the opportunity to evaluate other potentially associated factors with lung cancer such as occupation, toxic exposure, smoking, serum lipids, and other nutritional factors besides vitamin A. The information to be obtained from these studies would provide evidence for the suggested relationship between vitamin A (and/or other nutritional factors) and lung cancer. This information will also provide a scientific basis on which to make recommendations to the general population about the potential benefits of determined nutritional factors in the prevention of lung cancer.